A Randomized, Crossover, Adhesion Performance and Pharmacokinetic Study of a Lidocaine Topical System Under Conditions of Water Exposure in Healthy Subjects.

PURPOSE: This study compares the adhesion performance, pharmacokinetic profile, and safety of lidocaine topical system 1.8%, which is approved to treat postherpetic neuralgia, under conditions of swimming and showering versus normal conditions.

PATIENTS AND

METHODS

This open-label, 3-period, 3-treatment crossover study randomized 24 healthy adults to receive one lidocaine topical system during each of three treatment periods; subjects either swam in a heated swimming pool for 15 minutes 4.0 hours post-product application (swimming), showered for 10 minutes 8.0 hours after product application (showering), or the product remained dry throughout the treatment period (normal conditions). The product was applied to the mid-upper back and was removed after 12 hours. The pharmacokinetic profile of each subject under water exposure conditions was compared to subjects under normal conditions. Skin irritation, adhesion, and adverse events were assessed.

RESULTS

Twenty-four (24) subjects enrolled and 23 completed the study. Exposure to water resulted in lifting of the topical systems. There were two complete detachments, as well as seven occurrences of major lifting (more than 50% detached) after water exposure. The topical systems were immediately pressed down and/or reapplied after observing lifting and remained adhered to for the rest of the 12-hour application period. No clinically relevant differences in systemic absorption were observed under either showering or swimming conditions. The topical systems were well tolerated, with only mild adverse events, none leading to discontinuation.

CONCLUSION

These data show that while water exposure can cause the topical system to lift or detach, the lidocaine topical system 1.8% is capable of being reapplied and maintains adhesion for up to 12 hours of wear with no clinically significant changes in drug delivery.

CLINICALTRIALSGOV: NCT04784728.